Index: includes/common.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/common.inc,v
retrieving revision 1.1211
diff -u -p -r1.1211 common.inc
--- includes/common.inc	27 Aug 2010 11:54:32 -0000	1.1211
+++ includes/common.inc	27 Aug 2010 15:20:38 -0000
@@ -5528,7 +5528,7 @@ function element_children(&$elements, $s
   $children = array();
   $sortable = FALSE;
   foreach ($elements as $key => $value) {
-    if ($key[0] !== '#') {
+    if ($key === '' || $key[0] !== '#') {
       $children[$key] = $value;
       if (is_array($value) && isset($value['#weight'])) {
         $sortable = TRUE;
Index: modules/simpletest/tests/form.test
===================================================================
RCS file: /cvs/drupal/drupal/modules/simpletest/tests/form.test,v
retrieving revision 1.62
diff -u -p -r1.62 form.test
--- modules/simpletest/tests/form.test	27 Aug 2010 11:54:32 -0000	1.62
+++ modules/simpletest/tests/form.test	27 Aug 2010 15:20:38 -0000
@@ -50,7 +50,7 @@ class FormsTestCase extends DrupalWebTes
     $elements['textarea']['element'] = array('#title' => $this->randomName(), '#type' => 'textarea');
     $elements['textarea']['empty_values'] = $empty_strings;
 
-    $elements['radios']['element'] = array('#title' => $this->randomName(), '#type' => 'radios', '#options' => array($this->randomName(), $this->randomName(), $this->randomName()));
+    $elements['radios']['element'] = array('#title' => $this->randomName(), '#type' => 'radios', '#options' => array('' => t('None'), $this->randomName(), $this->randomName(), $this->randomName()));
     $elements['radios']['empty_values'] = $empty_arrays;
 
     $elements['checkbox']['element'] = array('#title' => $this->randomName(), '#type' => 'checkbox', '#required' => TRUE, '#title' => $this->randomName());
@@ -59,7 +59,7 @@ class FormsTestCase extends DrupalWebTes
     $elements['checkboxes']['element'] = array('#title' => $this->randomName(), '#type' => 'checkboxes', '#options' => array($this->randomName(), $this->randomName(), $this->randomName()));
     $elements['checkboxes']['empty_values'] = $empty_arrays;
 
-    $elements['select']['element'] = array('#title' => $this->randomName(), '#type' => 'select', '#options' => array($this->randomName(), $this->randomName(), $this->randomName()));
+    $elements['select']['element'] = array('#title' => $this->randomName(), '#type' => 'select', '#options' => array('' => t('None'), $this->randomName(), $this->randomName(), $this->randomName()));
     $elements['select']['empty_values'] = $empty_strings;
 
     $elements['file']['element'] = array('#title' => $this->randomName(), '#type' => 'file');